三河牛成年母牛体尺体重性状遗传参数估计

摘要

旨在建立三河牛成年母牛体尺和体重性状遗传分析模型,估计群体遗传参数,为确立三河牛育种目标和制定选择指数提供基础参数.本研究以1997-2010年采集的内蒙古谢尔塔拉种牛场核心群4 491头三河牛48 946条体尺体重记录为研究材料,以体高、体斜长、胸围、管围、体重、腹围、背高、十字部高、胸深、胸宽、腰角宽、坐骨宽、尻长、头长、额宽15个成母牛体尺体重性状为研究对象,使用DMU软件的AI REML结合EM算法,配合多性状动物模型,以母牛月龄为固定效应,场年季和加性遗传效应为随机效应,估计各性状方差组分,计算遗传力和遗传相关,根据各性状育种值分析其遗传趋势.结果表明,成年母牛体高、体斜长、胸围、管围、体重、腹围、背高、十字部高、胸深、胸宽、腰角宽、坐骨宽、尻长、头长、额宽的遗传力分别为0.73±0.02、0.58土0.02、0.43士0.03、0.51±0.02、0.41±0.03、0.51±0.03、0.60±0.03、0.69±0.03、0.55±0.03、0.26±0.02、0.28±0.03、0.17±0.02、0.21±0.02、0.69±0.03、0.55土0.03.成年母牛体尺体重性状间遗传相关系数为-0.19～0.92,表型相关系数为-0.30～0.93.体高、背高、十字部高3个体高性状之间具有较高相关性,遗传相关系数为0.79～0.88,表型相关系数为0.76～0.93.与繁殖性能相关的体尺性状,如腰角宽、坐骨宽、尻长之间遗传相关较低(0.11～0.34),表型相关中等(0.50～0.83).三河牛成年母牛体尺体重性状,总体上属于中高遗传力性状,与繁殖相关的体尺性状间遗传相关较低;而体躯结构类性状之间遗传相关较高.应进一步加强三河牛选育体系的建设,在各经济重要性状的遗传水平上取得稳定进展.%This study was conducted to establish model for genetic analyses of adult body size and body weight in Sanhe cattle,and to estimate population genetic parameters,in order to provide foundational parameters for establishing breeding objective and forming selection index for Sanhe cattle.Body size and body weight data of 4 491 adult Sanhe cows were measured from 1997 to 2010,a total of 48 946 records were collected from Xiertala Cattle Farm of Inner Mongolia,where the nuclear herd for Sanhe cattle were located,and used for genetic analyses.The 15 body size and body weight traits included body height(BOH),body length (BI),chest girth (CG),cannon circumference (CC),body weight (BW),abdomen circumference (AC),back height (BAH),hip cross height(HCH),chest depth (CD),chest width (CW),hip width (HW),pin bone width (PBW),rump length (RL),head length (HL) and forehead width (FW).DMU package was used for genetic evaluation(AI-REML and EM algorithm) combined with multiple traits animal model,considering age of cow as fixed effect,farm-year-season and additive genetic effect as random effects.Heritabilities and genetic correlations were computed based on estimated variance components,and genetic trends of all traits were analyzed based on estimated breeding values.The results showed that the estimated heritabilities of BOH,BL,CG,CC,BW,AC,BAH,HCH,CD,CW,HW,PBW,RL,HL and FW in adult cows were 0.73±0.02,0.58± 0.02,0.43±0.03,0.51±0.02,0.41±0.03,0.51±0.03,0.60±0.03,0.69±0.03,0.55± 0.03,0.26±0.02,0.28±0.03,0.17±0.02,0.21±0.02,0.69±0.03 and 0.55±0.03,respec-tively.The genetic correlation coefficient among body size and weight traits for adult cows were from-0.19 to 0.92,and their phenotypic correlation coefficient were from-0.30 to 0.93.The genetic correlation coefficient among BOH,BAH and HCH were 0.79-0.88,and their phenotypic correlation coefficient were 0.76-0.93.Genetic correlation among HW,PBW and RL were low (0.11-0.34),and their phenotypic correlation were medium (0.50-0.83).The heritabilities of body size and body weight in adult Sanhe cows are medium to high inheritable traits in general.In which,low genetic correlation exists among traits related to reproduction performance,while higher genetic correlation exists among traits related to body structure.It is suggested that selection system for Sanhe cattle should be strengthened,so that genetic level of economically important traits could be improved steadily.